As everyone else has mentioned 2500 is very long for a picture book, even for a 40-page picture book. Sometimes they are more flexible with informational picture books but even those rarely go over 1300 or so, at 40 pages. Do consider revising it as a chapter book -- I've done this twice, successfully, with longer picture book manuscripts at the suggestion of editors and have ended up selling them as chapter books -- but remember that your picture book manuscript would have been read by adults and chapter books are more often read by children. This'll mean -- you guessed it! -- having a good hard look at vocabulary, sentence flow, and so on -- and you'll likely want to add in a subplot and lengthen the story overall. But wow, will you have fun!! Good luck!